Automated vacuum waste handling system

ABSTRACT

This invention relates to an automated vacuum liquid waste handling system having two or more waste vessels, with a liquid-level sensor, a means for filling the waste vessels with waste, a means for switching from the first waste vessel, once full, to one or more other waste vessels that are not full, and a means for simultaneously removing said waste from the first full waste vessel to output holding stations and filling another waste vessel so that waste collection is not interrupted.

BACKGROUND OF THE INVENTION

The collection of depleted and contaminated chemicals from chemicalprocessing equipment is an important facet of all manufacturingprocesses that utilize such chemicals. Where hazardous waste chemicalsare not properly controlled the manufacturing facilities that utilizethe chemicals can be shut down, resulting in significant and expensivelosses of material and equipment. Also, high-levels of volatile organiccompounds (VOCs) can be generated by waste chemicals, and the control ofsuch VOCs is a significant problem. Therefore, a need exists forreliable, automated waste chemical collection systems, and particularlysystems such as those liquid waste collection systems disclosed in U.S.Pat. Nos. 5,148,945 and 6,148,846. However, there is a need forimprovement of these systems.

As an example, high throughput screening instruments generate a largevolume of liquid waste. With existing high throughput screeninginstruments, the large volumes of liquid waste generated must beconstantly monitored and collected into waste bottles for disposal. Somedisadvantages with high throughput screening liquid waste disposal arethat it is currently a manual process and it can require waste disposalwhen robotics operators are not on-site.

Thus, a need still exists for a liquid waste management system with nohuman contact with waste and the waste bottles are emptied automaticallyat any time of the day, without requiring the presence of a roboticsoperator.

SUMMARY OF THE INVENTION

This invention relates to an automated vacuum liquid waste handlingsystem having two or more waste vessels, with a liquid-level sensor, ameans for filling the waste vessels with waste, a means for switchingfrom the first waste vessel, once full, to one or more other wastevessels that are not full, and a means for simultaneously removing saidwaste from the first full waste vessel to output holding stations andfilling another waste vessel so that waste collection is notinterrupted. The automated vacuum liquid waste handling system can toswitch back and forth, as needed, to one or more of the waste vessels aseach becomes either full or is emptied.

This invention also relates to an automatic process for handling liquidwaste that minimizes human contact with waste and allows full wastevessels to be emptied automatically at any time of the day, withoutrequiring an operator to be present. The automated vacuum liquid wastehandling system comprises using a vacuum and pressure system. The vacuumsystem draws the liquid waste from the liquid waste production sourceinto the waste vessel. As the fluid accumulates in the vessel the liquidlevel rises engaging liquid-level sensor when the vessel is full. Anelectronic system controller is connected to the liquid-level sensor inthe waste vessel as well as to the 2-way and 3-way control valves whichcontrol the flow of liquid waste throughout the system. The 2-way and3-way control valves are controlled by the electronic system controllerthat alters the flow of liquid waste between a plurality of wastevessels. When a high liquid level alarm signal is received from theliquid-level sensor the electronic system controller engages theappropriate control valves so that the flow of liquid waste is stoppedat the full vessel and the liquid waste in the full vessel is emptied atthe holding station using a removal pump. The flow of the liquid wasteis then activated and sent to an unfilled vessel thereby filling theunfilled vessel. After the full vessel is emptied the liquid-levelsensor signals the electronic system controller to engage theappropriate control valves to isolate the emptied vessel from theremoval pump. This and other aspects of the invention are realized upona review of the specification as a whole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of the automated vacuum liquid waste handling systemutilizing two waste vessels.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an automated vacuum liquid wastehandling system that minimizes human contact and allows full wastevessels to be emptied automatically at any time of the day, withoutrequiring an operator to be present.

As shown in FIG. 1 (illustrating a system with 2 waste vessels), theautomated vacuum waste handling system (50) comprises liquid wasteproduction source (19), liquid waste supply lines (9) and (10) eachhaving at least one 2-way control valve (12) and (13), liquid wastevessels (1) and (11) each having liquid-level sensors (22) and (33),respectively, and three openings (5), (6) and (7) and (5 a), (6 a) and(7 a), respectively, liquid waste output lines (10 a) and (9 a) eachhaving at least one 2-way control valve (12 a) and (13 a), removal pump(40), vacuum source lines (10 b) and (9 b), each vacuum source linehaving a 3-way control valve (14) and (15) attached thereto, vacuum pump(20) and T-joints (2), (3) and (4).

The liquid waste production source (19) is connected to liquid wastesupply lines (9) and (10) by a T-joint (2). The 2-way control valve (13)and (12) on each liquid waste supply line (9) and (10) is located afterT-joint (2) and before waste vessels (1) and (11), respectively.

Liquid waste vessel (1) and (11) each have three openings, (5), (6) and(7) and (5 a), (6 a) and (7 a), respectively. Liquid waste supply line(10) is attached to liquid waste vessel (1) through opening (5). Liquidwaste output line (10 a) is connected to liquid waste vessel (1) throughopening (7). Vacuum source line (10 b) is connected to liquid wastevessel (1) through opening (6). Liquid waste output line (10 a)containing at least one 2-way control valve (12 a) attached thereto andis connected to a removal pump (40) by T-joint (3). Vacuum source line(10 b) having at least one 3-way control valve (14) attached thereto andis connected to vacuum pump (20) by T-joint (4).

Liquid waste supply line (9) is attached to liquid waste vessel (11)through opening (5 a). Liquid waste output line (9 a) is connected toliquid waste vessel (11) through opening (7 a). Vacuum source line (9 b)is connected to liquid waste vessel (11) through opening (6 a). Liquidwaste output line (9 a) containing at least one 2-way control valve (13a) attached thereto and is connected to removal pump (40) by T-joint(3). Vacuum source line (9 b) having at least one 3-way control valve(15) attached thereto and is connected to vacuum pump (20) by T-joint(4).

Removal pump (40) is connected to dump line (30), which is connected toan output holding station (31). The liquid-level sensors (22) and (33),2-way control valves (12), (13), (12 a), (13 a) and 3-way control valves(14) and (15) are connected to an electronic system controller (60) thatcontrols the flow of liquid waste throughout the waste handling system.The electronic system controller (60) engages the appropriate controlvalves so that liquid waste vessel (1) or (11) is emptied when full orfilled when empty, which ever is appropriate.

In operation, the automated vacuum liquid waste handling system (50)pumps liquid waste through liquid waste supply lines depending uponwhich line is open. When one liquid waste supply line is open theother(s) is closed.

Using FIG. 1 as a model, when liquid waste supply line (10) is opened,generally this means 2-way control valve (12) is open, 3-way controlvalve (14) is open to vacuum pump (20) and 2-way control valve (12 a) isclosed to removal pump (40). Liquid waste is then pumped, using vacuumpump (20) from liquid waste production source (19) through liquid wastesupply line (10) to liquid waste vessel (1). Liquid waste is collectedin liquid waste vessel (1) until it becomes full at which time theliquid-level sensor(22) is activated. This signals the electroniccontrol system (60) to close 2-way control valve (12); switch 3-waycontrol valve (14) to release the vacuum on liquid vessel (1); open2-way control valve (13) to accept liquid waste and send it to liquidvessel (11); switch 3-way control valve (15) to vacuum pump (20) toprovide vacuum to liquid waste vessel (11); open 2-way control valve (12a); and activate removal pump (40) to draw waste from liquid wastevessel (1). Once liquid waste vessel (1) is empty liquid-levelsensor(22) is activated signaling the electronic controll system (60) toclose 2-way control valve (12 a) and shut off removal pump (40).

Once liquid waste vessel (11) becomes full the liquid-level sensor means(33) is activated, which signals the electronic control system (60) toclose 2-way control valve (13), switch 3-way control valve to releasethe vacuum on liquid vessel (11); open 2-way control valve (12) toaccept waste to liquid waste vessel (1); open 3-way control valve (14)to vacuum pump (20) allowing vacuum to liquid vessel (1); open 2-waycontrol valve (13 a) and activate removal pump (40) to draw waste fromliquid waste vessel (11). Once liquid waste vessel (11) is emptyliquid-level sensor (33) is activated thereby signalling 2-way controlvalve (13 a) to close and shutting off removal pump (40).

The automated vacuum liquid waste handling system of the claimedinvention is comprised of at least two liquid waste vessels. When thereare three or more liquid waste vessels the system can be set up to filland/or empty the vessels in succession or some other pre-determinedorder. Alternatively, the liquid waste handling system can be set up tooperate by modules. For example, it can have two modules, module A,having liquid waste vessels 1 and 2 and module B, having liquid wastevessels 3 and 4. In this example liquid waste vessel 1 can collectliquid waste until it is filled at which point it stops collecting andliquid waste vessel 2 begins to collect waste until it is filled. Onceliquid waste vessel 2 is filled Module A can be trigger to beginemptying the vessels and liquid vessel 3 of module B can begincollecting liquid waste until it is filled at which point liquid wastevessel 4 begins collecting liquid waste. Each module can be controlledby a separate electronic system controller, or a single electronicsystem controller can be used. As one skilled in the art can imagine,there are many ways that the liquid waste can be collected with amulti-waste vessel system.

Liquid-level sensor means that can be used in this invention are thoseknown in the art. Examples are those that have a 2-point float switch,ultrasonic sensor, magnetostrictive sensor or any other continuousliquid level measurement sensors. Generally, the 2-point sensor has afloat switch that rises as the waste vessel is filled with liquid waste,such that when the float switch reaches the top of the vessel, thesensor is activated. Additionally, when the waste vessel is emptied, thefloat switch falls, such that when the float switch is at the bottom ofthe vessel the sensor is activated and signals that the waste vessel isempty. An example of a 2-point sensor is GEMS LS-700. Theliquid-level-capacity sensor serves to detect when the liquid level inthe vessel is empty or full. Thus, the sensor has a dual function. Whena waste vessel is empty, the sensor in this vessel signals theelectronic system controller to open the control valves responsible forfilling the vessel. When a waste vessel is full the sensor in thisvessel signals the electronic system controller to close the controlvalves responsible for filling the vessel and open the control valvesresponsible for emptying the vessel.

Electronic system controller that can be used in this invention areknown in the art and are analog, digital, or a combination. When theliquid-level-capacity sensor is activated the electronic systemcontroller (60) engages the appropriate control valves so that the flowof liquid waste throughout the system is controlled.

Examples of known two-way and three-way control valves that can be usedin this invention are solenoid, ball valve, elliptical valve, diaphragmvalve, needle valve and the like. The control valve should be one thatis resistant to caustic fluids, if caustic fluids are being used. TheASCO Valve is an example of a two-way control valve.

1. An automated vacuum liquid waste handling system comprising: aplurality of waste vessels, each having a liquid-level sensor and threeopenings, a means for filling a first waste vessel with liquid waste, ameans for switching from the first waste vessel, once full, to a secondwaste vessel that is not full, and a means for simultaneously removingsaid waste from the first full waste vessel to an output holding stationand filling the second waste vessel; said automated vacuum wastehandling system being able to switch back and forth, as needed, to twoor more waste vessels as each becomes full or is emptied.
 2. Anautomated vacuum liquid waste handling system according to claim 1,wherein the means for filling the first waste vessel comprises: (1) aliquid waste production source, (2) a vacuum pump, (3) a first wastesupply line having a first 2-way control valve, (4) a first waste outputline having a second 2-way control valve, (5) a first vacuum source linehaving a 3-way control valve, and (6) at least one T-joint; said firstwaste supply line for providing access to or isolating the first wastevessel from the liquid waste production source, and being connected tothe liquid waste production source by a first T-joint; said first wastesupply line connected to the first liquid waste vessel through a firstopening in said first liquid waste vessel; said first waste output line,being connected through a second opening in the first liquid wastevessel for retaining or releasing the liquid waste in the first liquidwaste vessel; said first vacuum source line for providing or releasingvacuum to the first liquid waste vessel and being connected to the firstliquid waste vessel through a third opening in the first liquid wastevessel; said vacuum pump connected to the first vacuum source line,having the 3-way control valve, by a third T-joint for pumping liquidwaste from the liquid waste production source to the liquid wastevessels; and said first T-joint for connecting the liquid wasteproduction source to the second waste vessel.
 3. An automated vacuumliquid waste handling system according to claim 1, wherein saidswitching means comprises: (1) a liquid-level sensor located within eachof the liquid waste vessel(s), and (2) an electronic system controller,said liquid-level sensor signals the electronic system controller thatthe liquid waste vessel is full or empty; said electronic systemcontroller engages the appropriate control valves so that the liquidwaste vessels are emptied when full and filled when emptied.
 4. Anautomated vacuum liquid waste handling system according to claim 1,wherein the means for simultaneously removing said waste from the firstfull waste vessel to an output holding station and filling the secondliquid waste vessel comprises: (1) a first liquid waste output linehaving a second 2-way control valve, (2) one or more T-joints (3) aremoval pump, (4) a liquid waste production source, (5) a vacuum pump,(6) a second liquid waste supply line having a third 2-way controlvalve, (7) a second liquid waste output line having a fourth 2-waycontrol valve, (8) a second vacuum source line having a 3-way controlvalve, said first liquid waste output line having the ssecond 2-waycontrol valve, being connected to the removal pump by a second T-jointthrough a dump line; said removal pump for removing the liquid wastefrom a first liquid waste vessel through the liquid waste output linethrough the dump line to the output holding station; said second 2-waycontrol valve for retaining or releasing the liquid waste in a firstliquid waste vessel; said second T-joint further connected to the secondliquid waste output line having the fourth 2-way control valve forretaining or releasing the liquid waste in the second liquid wastevessel, and being connected to the second liquid waste vessel through asecond opening in the second liquid waste vessel; said second liquidwaste supply line having the third 2-way control valve for providingaccess to or isolating the second waste vessel from the liquid wasteproduction source, and being connected to the liquid waste productionsource by a first T-joint; said second liquid waste vessel beingconnected to the second waste supply line through a first opening in thesecond liquid waste vessel; said second vacuum source line having a3-way control valve, the 3-way control valve for providing or releasingvacuum to the second liquid waste vessel and being connected to thesecond liquid waste vessel through a third opening in the second liquidwaste vessel; said vacuum pump connected to the second vacuum sourceline by a third T-joint for pumping liquid waste from the liquid wasteproduction source to the second liquid waste vessel; and said firstT-joint for connecting the liquid waste production source to a firstliquid waste vessel and the second liquid waste vessel.
 5. An automatedvacuum liquid waste handling system comprising: (1) a liquid wasteproduction source, (2) vacuum pump, (3) a first waste supply line havinga first 2-way control valve, (4) a first waste output line having asecond 2-way control valve, (5) a first vacuum source line having a3-way control valve, and (6) at least one T-joint; (7) a plurality ofliquid waste vessels each having a liquid level sensor, (8) anelectronic system controller, (9) a second liquid waste supply linehaving a third 2-way control valve, (10)a second liquid waste outputline having a fourth 2-way control valve, and (11)a second vacuum sourceline having a 3-way control valve, said first waste supply line havingthe first 2-way control valve for providing access to or isolating thefirst waste vessel from the liquid waste production source, and beingconnected to the liquid waste production source by a first T-joint; saidfirst waste supply line connected to the first liquid waste vesselhaving the liquid level sensor through a first opening in said firstliquid waste vessel; said first waste output line having the second2-way control valve, for retaining or releasing the liquid waste in thefirst liquid waste vessel, and being connected through a second openingin the first liquid waste vessel; said first vacuum source line havingthe 3-way control valve for providing or releasing vacuum to the firstliquid waste vessel and being connected to the first liquid waste vesselthrough a third opening in the first liquid waste vessel; said vacuumpump connected to the first vacuum source line by a third T-joint forpumping liquid waste from the liquid waste production source to theliquid waste vessels; said first T-joint for connecting the liquid wasteproduction source to the second of waste vessel, having a liquid levelsensor; said second liquid waste supply line for providing access to orisolating the second liquid waste vessel from the liquid wasteproduction source through use of the third 2-way control valve, andbeing connected to the liquid waste production source by the firstT-joint; said second waste supply line connected to the second liquidwaste vessel through a first opening in said second liquid waste vessel;said second waste output line having the fourth 2-way control valve, forretaining or releasing the liquid waste in the second liquid wastevessel, and being connected to the second liquid waste vessel through asecond opening in the second liquid waste vessel; said second vacuumsource line having the second 3-way control valve for providing orreleasing vacuum to the second liquid waste vessel and being connectedto the second liquid waste vessel through a third opening in the secondliquid waste vessel; said vacuum pump connected to the second vacuumsource line by a third T-joint for pumping liquid waste from the liquidwaste production source to the second liquid waste vessel; said firstT-joint for connecting the liquid waste production source to the firstand second liquid waste vessels, said liquid-level sensor for signallingthe electronic system controller that the liquid waste vessel is full orempty; and said electronic system controller for engaging appropriatecontrol valves so that the liquid waste vessels are emptied when full orfilled when emptied.
 6. An automated vacuum liquid waste handling systemaccording to claim 5 wherein the liquid-level sensor in the first liquidwaste vessel signals the electronic system controller, when the firstwaste vessel is full, to close the first 2-way control valve, switch thefirst 3-way control valve so that it releases vacuum from the firstliquid waste vessel, switch the second 3-way control valve to providevacuum to the second liquid waste vessel, open the third 2-way controlvalve so that liquid waste from the liquid waste production source goesinto the second liquid waste vessel and begins filling it, open thesecond 2-way control valve to release the liquid waste from the firstliquid waste vessel into a liquid waste output holding station; saidsecond 2-way control valve closing once liquid-level sensor in the firstliquid waste vessel signals the electronic system controller that firstliquid waste vessel is empty, when the second liquid waste vessel isfull the liquid-level sensor in the second liquid waste vessel signalsthe electronic system controller to close the third 2-way control valve,switch the second 3-way control valve so that it releases vacuum fromthe second liquid waste vessel, switch the first 3-way control valve toprovide vacuum to the first liquid waste vessel, open the first 2-saycontrol valve so that liquid waste from the liquid waste productionsource goes into the first liquid waste vessel and begins filling it,open the fourth 2-way control valve to release the liquid waste from thesecond liquid waste vessel into a liquid waste output holding stationthereby starting the process over again; said fourth 2-way control valveclosing once liquid-level sensor in the second liquid waste vesselsignals the electronic system controller that second liquid waste vesselis empty.
 7. An automated vacuum liquid waste handling system accordingto claim 2 wherein the 2-way and 3-way control valves are independentlyselected from the group consisting of solenoid valve, ball valve,elliptical valve, diaphragm valve, and needle valve.
 8. An automatedvacuum liquid waste handling system according to claim 3 wherein theliquid level capacity sensor means is selected from the group consistingof 2 point float switch, ultrasonic sensor, magnetostrictive sensor orany continuous liquid level measurement sensor.
 9. A process forhandling liquid waste automatically comprising (1) pumping liquid wastefrom a liquid waste production source through a first liquid wastesupply line to a first liquid waste vessel having a liquid-level sensor,a first waste output line and a first vacuum source line, said firstliquid waste supply line and waste output line having a first 2-way andsecond 2-way control valve, respectively and said first vacuum sourceline having a 3-way control valve; (2) collecting the liquid waste inthe first waste vessel until it is full; (3) switching to a secondliquid waste vessel thereby stopping the collection of liquid waste inthe first waste vessel; (4) collecting the liquid waste in a secondliquid waste vessel until it is full; (5) emptying the first liquidwaste vessel while liquid waste is collecting in the second liquid wastevessel, wherein the switching to a second waste vessel is controlled byan electronic system controller activated by the liquid-level sensor,said liquid-level sensor for detecting when the first waste vessel isempty or full, said electronic system controller closing the first 2-waycontrol valve to prevent liquid waste from entering the first fullliquid waste vessel, opening the second 2-way control valve that islinked to a removal pump and switching the first 3-way control valve torelease vacuum on the first liquid waste vessel so that it is emptied toa liquid waste output holding station, said electronic system controllerat the same time closes the first 2-way control valve, opens a third2-way control valve and switches a second 3-way control valve to supplyvacuum to the second liquid waste vessel so that it begins to fill withliquid waste, once the second liquid waste vessel is full theliquid-level sensor in the second waste vessel causes the electronicsystem controller to close the third 2-way control valve to preventliquid from entering the second liquid waste vessel, open a fourth 2-waycontrol valve that is linked to the removal pump and switch a second3-way control valve to release vacuum on the second liquid waste vesselso that it is emptied to a liquid waste output holding station; saidelectronic system controller signaling the first 2-way control valve andthird 3-way control valve to begin filling the first empty waste vesseland thereby providing a continuous liquid waste handling system.
 10. Aprocess according to claim 9 which contains two or more liquid wastevessels, four or more 2-way control valves and two or more 3-way controlvalves.